Resolution Revolution

High-rez music is the most exciting audio development to come along in years, and I’ve written quite a bit about it. But I’ve received enough questions concerning high-rez that I felt it was time to devote a column to the subject. What follows is a primer that touches on the basics of high-rez music: what it is, how to get it, and how to play it.

What’s High-Rez?

High-rez music refers to audio files that contain more information than the Red Book CD format, which samples audio at a 44.1-kHz rate with 16-bit resolution. High-rez music, in contrast, is typically sampled at a 96-kHz rate with 24-bit resolution. (Though there are some “ultra-high-rez” 192/24 releases that are captured with an even higher 192-kHz sampling rate. Well, hello, Mr. Neil Young....) And unlike the music found at the iTunes store, which is packaged for download using a lossy encoding format called AAC, high-rez music downloads typically use a lossless compression format called FLAC that doesn’t toss any information out in the interest of saving hard-drive space. The result is that high-rez music has a greater sense of depth, with air around individual instruments, more nuanced vocals, and, depending on the production, a better sense of the environment where the recording was made.

Sizing Things Up

Let’s put high-rez file size into perspective. A typical 3-minute iTunes song download takes up a little over 6 MB of space. A high-rez 96/24 download of that same song will take up around 65 MB. A 192/24 file, meanwhile, may require 133 MB for a single song. Thus, high-rez albums typically take up a gigabyte or more of space — not really a problem in this cheap ’n’ capacious hard-drive era.

The Source

High-rez audio made a brief go at the mass market a few years ago in the form of Super Audio CD (SACD) and DVD-Audio discs. While there are still discs available in both formats, new releases have slowed to a trickle. Another way to access high-rez audio, and to find the largest selection of titles, is to download them from HDtracks.com. HDtracks offers a free five-track sampler, which is a great way to experience high-rez music and also ensure that your equipment supports playback of high-rez files. Two additional sites to check out are itrax.com and the Bowers & Wilkins Society of Sound.

Play Time

Many music streamers and recent-model A/V receivers can handle high-rez FLAC files, so if you own one of these, you should be all set. Simply connect a USB drive containing the fi les to your equipment, sit back, and enjoy. Unfortunately, just looking over your hardware’s specs won’t necessarily tell you if it handles high-rez. For example, a NAD C446 music streamer that I recently reviewed had 192/24-capable DACs, but wouldn’t play high-rez files in any format. My Marantz AV7005 receiver also has 192/24 DACs, but playback on it is limited to 96/24 files, not 192/24 ones.

On the software side, many people use WMP or iTunes as their network music server by simply setting up a shared “My Music” (WMP) or iTunes Library folder. But neither WMP nor iTunes supports FLAC, so files in that format simply won’t appear when you attempt to stream them. The solution is to have a separate program running on your computer that acts as the server. I use JRiver Media Center (jriver.com) on my PC, which offers a ton of features, including file conversion, but there are others like Twonky (compatible with Macs) and Media Monkey. When one of these server programs is running, high-rez files will appear in your hardware’s onscreen GUI or front-panel display, and then you can stream them just like any other song. I’ve found that 96/24 files work fairly well when streamed via Wi-Fi, but 192/24 files tend to sound choppy and should ideally be streamed over a hardwired LAN.

The big question: Is high-rez music really worth it? In my experience, the answer is yes. It sounds better and is far less fatiguing to listen to at high volumes. Download the HDtracks.com free sampler and experience the revolution for yourself.